The changes are understood to include a weather test which could lead to the selection week being postponed if the weather is too hot, cold or humid, according to The Times newspaper.

It reported that practice sessions will be introduced to enable reservists to become accustomed to the terrain and the paper also said there would be more water stations along routes through the Brecon Beacons.

The Times said the changes will apply to the aptitude test week for the regular and the reserve SAS from next year.

Speaking to ITV News, one former Army officer called the reports "awfully sad news", adding: "Any lessening of standards would be a step in the wrong direction."

Interview with Major (ret) Alan Davies:

Last month, senior Birmingham coroner Louise Hunt said three soldiers would have survived if Ministry of Defence regulations on heat illness had been followed.

Lance Corporals Edward Maher and Craig Roberts were pronounced dead on the Brecon Beacons after suffering heatstroke in July 2013.

Corporal James Dunsby died at Birmingham's Queen Elizabeth Hospital from multiple organ failure more than two weeks later.

Describing parts of the planning and conduct of the special forces march as inadequate or not fit for purpose, the coroner said inadequate supplies of water also contributed to one of the deaths.